Microwave hydrothermal synthesis and photocatalytic properties of ZnWO4 nanorods

Cd2+-doped ZnWO4 nanorods have been synthesized at 200 C with microwave hydrothermal method, using Zn(NO3)2.6H2O, Na2WO4.2H2O and CdCl2 as raw materials. The effects of Cd2+ doping contents on the structure and morphology of the product were studied. The results show that Cd2+ doping into the crystal lattice of ZnWO4 nanopowder makes the powder orientationally grow along (010), (110) and (200) crystal planes to form the nanorods. The bigger Cd2+ doping contents are, the more obviously ZnWO4 nanorods grow. Meanwhile, the nanopowder is gradually transformed from monoclinic phase into the orthogonal phase. As the charge transference medium between the interfaces, Cd2+ restrains the combination of holes and electrons. After doped, the photocatalytic properties of ZnWO4 nanorods are increased. When Cd2+ doping content is 20%, the Cd2+-doped ZnWO4 nanorods showed the highest degradation rate up to 98% in 2 h. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)